It is known to produce preparations based on alginates for use as appetite curbing agents in slimming diets. Since these preparations swell in the stomach and intestinal tract, they produce a feeling of fullness and satisfaction in human beings. However, the preparations have a considerable disadvantage in that in the presence of calcium ions they form calcium-containing deposits of low solubility. As a result, it is possible for a calcium ion deficiency to be produced, particularly in the intestinal tract. The fear has therefore often been voiced that disturbances of the metabolism could thereby be produced.